During handover of a mobile terminal in a wireless communication network, control of an ongoing wireless communication session involving the mobile terminal is transferred from one network node, e.g., a source base station, to another network node, e.g., a target base station. Handover is performed as the mobile terminal moves out of the area covered by the source base station and into the area covered by the target base station.
Wireless networks typically use handover triggers to initiate or trigger handover of the mobile terminal from the source base station to the target base station. Both simulation results and field trials show that the optimal handover trigger substantially reduces the handover failure rate and improves system and service performance. Thus, overall performance of the wireless communication network relies on the careful choice of the handover trigger(s). This is particularly true for networks associated with different access technologies and/or standards (e.g., heterogeneous networks), where the wrong handover trigger causes more pronounced problems than in homogeneous networks.